Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 1083-1085

Titre :	Temperature - induced irreversible change of ZnO optical energy gap
Type de document :	texte imprimé
Auteurs :	Yan Huo, Auteur ; Yun Hang Hu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 1083-1085
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Optical energy
Résumé :	It is generally recognized that the change of ZnO optical properties due to high-temperature treatment is reversible. However, herein, it is reported that high-temperature treatment in air caused an irreversible decrease in ZnO optical energy gap (Eg). The irreversible decrease in Eg was enhanced with increasing treatment temperature. Furthermore, it was found that the irreversible decrease in Eg can be attributed to the enlargement of ZnO crystal particles.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476441

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 1073-1082

Titre :	Multiphase CFD simulation of flow inside liquid seal drums of the refinery flare system
Type de document :	texte imprimé
Auteurs :	Randheer Yadav, Auteur ; Amitkumar Parekh, Auteur ; Ajay Gupta, Auteur
Année de publication :	2012
Article en page(s) :	pp. 1073-1082
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Refinery Drum Seal Computational fluid dynamics
Résumé :	The present work deals with improving the reliability of the liquid seal drum in the refinery flare system. CFD (based on volume of fluid concept) as well as theoretical modeling have been used for deciphering the hydrodynamics in two different designs (designated as design-1 and design-2) of the liquid seal drums. Results of the CFD simulations showed that the internals present in design-1 facilitate in bubble coalescing, thus resulting in large sized Taylor bubbles, which cause large fluctuations in the liquid level. Large level fluctuations create problems such as flare puffing, knocking, and dislodging of seal drum intemals. On the basis ofthe CFD model findings, a one-dimensional model based on Taylor bubble phenomenon1 has been adopted. Subsequently, the 1D model was used for calculating the Taylor bubble size and liquid level fluctuations. The 1D model was also used to predict the bubble size and liquid level fluctuation in another design (design-2) of the seal drum. Design-2 was also tested using CFD, which shows smooth passage of flare gas in the form of small bubbles with little fluctuation in liquid level On the basis of the study, it was suggested to change the design-1 by design-2. Suggestions were implemented in the plant, which relieved it of problems faced with design-1. This led to reliability improvement and substantial monetary benefits.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476440

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 1062-1072

Titre :	Gas hydrate phase equilibrium in porous media : Mathematical modeling and correlation
Type de document :	texte imprimé
Auteurs :	Amir H. Mohammadi, Auteur ; Ali Eslamimanesh, Auteur ; Richon, Dominique, Auteur
Année de publication :	2012
Article en page(s) :	pp. 1062-1072
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Correlation analysis Correlation Modeling Porous medium Phase equilibrium Gas hydrates
Résumé :	In this paper, we present two different approaches to represent/predict the gas hydrate phase equilibria for the carbon dioxide, methane, or ethane + pure water system in the presence of various types of porous media with different pore sizes. The studied porous media include silica gel, mesoporous silica, and porous silica glass. First, a correlation is presented, which estimates the hydrate suppression temperature due to the pore effects from the ice point depression (IPD). In the second place, several mathematical models are proposed using the least squares support vector machine (LSSVM) algorithm for the determination of the dissociation pressures of the corresponding systems. The results indicate that although the applied correlation based on the (IPD) leads to obtaining reliable results for the gas hydrate systems in the presence of porous silica glass media, the developed LSSVM models seem to be more general due to their predictive capability over all of the investigated systems.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476439

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 1050-1061

Titre :	Discrete particle simulation of particle flow in a stirred mill : Effect of mill properties and geometry
Type de document :	texte imprimé
Auteurs :	C.T. Jayasundara, Auteur ; R.Y Yang, Auteur ; A. B. Yu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 1050-1061
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Solids flow
Résumé :	Particle flow in a stirred mill was modeled using discrete element method, focusing on the effect of mill properties and stirrer configurations, such as particle-wall friction, the size of disc holes, distance between stirrers, and stirrer shape, on the flow properties of grinding media. The flow properties were analyzed in terms ofvelocity field, porosity distribution, collision frequency, collision energy, impact energy, and power draw. The results indicate that although particle-wall sliding friction coefficient affects the energy transfer from discs to particles, too high a sliding friction may lead to a decrease in energy efficiency. The distance between discs significantly affects the circulation of grinding media between discs. Among the different stirrer types considered, energy transfer is more effective when disc holes are present. Pin stirrer shows increased grinding rates which also results in relatively high power consumption. Although different collision environments exist with different stirrer types, it is shown that the grinding rate can be determined by the first-order kinetics where the rate constant is dependent on the impact energy, for a given material. Grinding efficiency has been compared for different grinding materials under different operating conditions. The results suggest that selection of stirrer geometry also depends on the feed size and the type of material to be ground. Discussion has also been made of the usefulness of particle scale information in the design and control of stirred mills of different types.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476438

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 1041-1049

Titre :	Growth behavior of aragonite under the influence of magnetic field, temperature, and impurity
Type de document :	texte imprimé
Auteurs :	Steven S.S. Wang, Auteur ; Meng - Chun Chang, Auteur ; Huan - Chieh Chang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 1041-1049
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Impurity Magnetic field
Résumé :	With and without magnetization, the growth rates of aragonite seeds were measured in a stirred-tank crystallizer in the presence of Fe2+ or Sr2+ acting as an impurity at two temperature levels, using the constant-composition technique. The concentration range of the impurity investigated was between 0 and 2 ppm, and the temperature settings were either 25 or 35 °C. The individual factors each had a distinct effect on the growth rate of aragonite, and the combined effects became complicated, especially in the presence of Sr2+, which changed the surface structure of the aragonite seed dramatically.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476437

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 1036-1040

Titre :	Biodiesel from zophobas morio larva oil : Process optimization and FAME characterization
Type de document :	texte imprimé
Auteurs :	D. Leung, Auteur ; Depo Yang, Auteur ; Zhuoxue Li, Auteur
Année de publication :	2012
Article en page(s) :	pp. 1036-1040
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Optimization
Résumé :	The advancement of biodiesel production emphasizes the finding of new, low-cost, and plentiful raw materials. Insects, as one of the most plentiful biological resources worldwide, could be potential candidates for biodiesel production. In this study, Zophobas morio (Coleoptera: Tenebrionidae) was evaluated as an insect feedstock, attempting to prove the feasibility of producing qualified biodiesel. The oil content in dried Z. morio larvae was found to be 33.80 wt %. Biodiesel from Z. morio larva oil was prepared by acid esterification followed by alkaline transesterification. The parameters of the reaction were optimized at 1.25 wt % potassium hydroxide catalyst, a 5:1 methanol to oil ratio, a reaction temperature of 50 °C, and a reaction time of 45 min. Under these conditions, the maximum fatty acid methyl ester yield was 92.35 wt %. The biodiesel obtained was verified to be in compliance with the ASTM D6751 standard. This study supports the use of Z. morio larva oil as a viable and valuable raw feedstock for biodiesel production and indicates the potential use of insects as feedstock for applications in energy production.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476436

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 1027-1035

Titre :	Experimental and theoretical analysis of CO2 absorption in polyolester oil using the PC - SAFT equation of state to account for nonideal effects
Type de document :	texte imprimé
Auteurs :	Moisés A. Marcelino Neto, Auteur ; Jader R. Barbosa, Auteur
Année de publication :	2012
Article en page(s) :	pp. 1027-1035
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Thermodynamic properties Equations of state Gas absorption Carbon dioxide
Résumé :	The purpose of this work is to study the absorption of carbon dioxide (CO2) through the free surface of a stagnant layer of polyolester oil in a closed cell via the pressure decay method. The system pressure and local temperatures in the vapor and liquid phases were recorded as a function of time for system temperatures of 25, 40, 55, and 70 °C. The tests were carried out for two initial heights of the liquid layer of 37 and 74 mm, respectively. The mass of CO2 that entered the cell was measured for each test. The data were used to validate a transient mass diffusion model that accounts for the departure from the ideal behavior. The model uses the PC-SAFT equation of state and incorporates the following nonideal effects: (i) gas compressibility in the vapor, (ii) liquid phase swelling, (iii) concentration-dependent nonideal density behavior, (iv) nonideal phase equilibrium at the vapor―liquid interface, and (v) concentration-dependent mass diffusivity. Absorption rates were found to be strongly dependent on, and inversely proportional to, the system temperature. The absolute average errors of the absolute pressure prediction were lower than 4%. When the nonideal effects are ignored, the absolute average errors can be as large as 30%.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476435

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 1015-1026

Titre :	Liquid – liquid flow in a capillary microreactor : Hydrodynamic flow patterns and extraction performance
Type de document :	texte imprimé
Auteurs :	Jovan Jovanovic, Auteur ; Evgeny V. Rebrov, Auteur ; T. A. (Xander) Nijhuis, Auteur
Année de publication :	2012
Article en page(s) :	pp. 1015-1026
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Flow field Hydrodynamics Microreactor Liquid liquid flow
Résumé :	The capillary microreactor, with four stable operating flow patterns and a throughput range from grams per hour to kilograms per hour, presents an attractive alternative to chip-based and microstructured reactors for laboratory- and pilot-scale applications. In this article, results for the extraction of 2-butanol from toluene under different flow patterns in a water/toluene flow in long capillary microreactors are presented. The effects of the capillary length (0.4―2.2 m), flow rate (0.1-12 mL/min), and aqueous-to-organic volumetric flow ratio (0.25―9) on the slug, bubbly, parallel, and annular flow hydrodynamics were investigated. Weber-number-dependent flow maps were composed for capillary lengths of 0.4 and 2 m that were used to interpret the flow pattern formation in terms of surface tension and inertia forces. When the capillary length was decreased from 2 to 0.4 m, a transition from annular to parallel flow was observed. The capillary length had little influence on slug and bubbly flows. The flow patterns were evaluated in terms of stability, surface-to-volume ratio, throughput, and extraction efficiency. Slug and bubbly flow operations yielded 100% thermodynamic extraction efficiency, and increasing the aqueous-to-organic volumetric ratio to 9 allowed for 99% 2-butanol extraction. The parallel and annular flow operating windows were limited by the capillary length, thus yielding maximum 2-butanol extractions of 30% and 47% for parallel and annular flows, respectively.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476434

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 1006–1014

Titre :	Solution of the span – wagner equation of state using a density – energy state function for fluid - dynamic simulation of carbon dioxide
Type de document :	texte imprimé
Auteurs :	Knut Erik Teigen Giljarhus, Auteur ; Svend Tollak Munkejord, Auteur ; Geir Skaugen, Auteur
Année de publication :	2012
Article en page(s) :	pp. 1006–1014
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Fluid dynamic Carbon Dioxide
Résumé :	With the introduction of carbon capture and storage (CCS) as a means to reduce carbon emissions, a need has arisen for accurate and efficient simulation tools. In this work, we propose a method for dynamic simulations of carbon dioxide using the Span–Wagner reference equation of state. The simulations are based on using the density and internal energy as states, which is a formulation naturally resulting from mass and energy balances. The proposed numerical method uses information about saturation lines to choose between single-phase and two-phase equation systems, and is capable of handling phase transitions. To illustrate the potential of the method, it is applied to simulations of tank depressurization, and to fluid-dynamic simulations of pipe transport.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201748a

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 994-1005

Titre :	Characterization of the hydrodynamics and mixing performance of a split - and - recombination (SAR) prototype microreactor and a multilamination commercial microreactor
Type de document :	texte imprimé
Auteurs :	Lionel S. Méndez-Portillo, Auteur ; Louis Fradette, Auteur ; Charles Dubois, Auteur
Année de publication :	2012
Article en page(s) :	pp. 994-1005
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Microreactor Mixing Hydrodynamics
Résumé :	The aim of this work was to quantify the performance of two well-known mixing mechanisms used in microreactors: the split-and-recombination (SAR) and the multilamination by means of an interdigital structure. The residence time distribution (RTD) and the mixing performance in laminar flow regime were experimentally characterized by the tracer pulse-input technique and the iodide-iodate Villermaux/Dushman method. RTD analysis indicates bypassing caused by uneven flow distribution in the manifolds of both microreactors. A decrease of the quadratic dependence of axial dispersion on fluid velocity is produced by the improved tracer homogenization achieved in the microfluidic structures. The iodide-iodate method shows that below a critical Damköhler number the microreactors exhibit a superior mixing performance than a conventional T-junction. The interdigital microreactor displayed the best mixing capabilities for all the flow conditions investigated. However, the estimation of energy dissipation confirms that the improved mixing performance of the interdigital unit is obtained at the expense of greater energy expenditure when compared with the split-and-recombination microreactor.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476432

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 978–993

Titre :	PVDF / Nanosilica dual - layer hollow fibers with enhanced selectivity and flux as novel membranes for ethanol recovery
Type de document :	texte imprimé
Auteurs :	Panu Sukitpaneenit, Auteur ; Tai-Shung Chung, Auteur
Année de publication :	2012
Article en page(s) :	pp. 978–993
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nanosilica Ethanol
Résumé :	In this work, we have demonstrated the design and engineering of poly(vinylidene fluoride) (PVDF)/nanosilica dual-layer hollow fibers as novel pervaporation membranes for ethanol recovery. The newly developed dual-layer hollow fiber membrane can exhibit a high separation factor of up to 29 with a sustainable high flux of 1.1 kg m–2 h–1, which is equivalent to the separation performance regime of inorganic membranes. Central to this performance achievement is the synergy of (1) desirable membrane morphology, nanopore size, and high surface porosity of a thin-PVDF/nanosilica composite on a fully porous substrate accomplished by the dual-layer coextrusion technology, and (2) optimal operating downstream pressure with the aid of controlled pervaporation transport. The membrane selectivity-downstream pressure dependence of PVDF/nanosilica hybrid membranes is comprehensible via a modified pore-flow model. This study may represent a new class of membranes for ethanol–water separation.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202116h

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 972-977

Titre :	Selective uptake by akaganeite (B - FeOOH) of phosphite from hypophosphite and phosphite solutions
Type de document :	texte imprimé
Auteurs :	Ramesh Chitrakar, Auteur ; Yoji Makita, Auteur ; Takahiro Hirotsu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 972-977
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Uptake
Résumé :	The anion-exchange properties of akaganeite (β-FeOOH) with phosphite (H2PO3― and HPO32― ) are reported herein. Uptake of phosphite by akaganeite followed the Freundlich isotherm model with exchange capacity of 1.0 mmol/g, and high distribution coefficients in multianion solution of 2.0 mmol/dm3 concentration (7.0 x 103 cm3/g at pH 3.9). Akaganeite displayed nearly constant uptake of phosphite (0.9 mmol/g) at pH 2.5―6.0. The kinetics on uptake of phosphite rapidly reached an equilibrium in 4 h. Akaganeite was also found to be feasible for high uptake of phosphite (1.2 mmol/g) and low uptake of hypophosphite (<0.10 mmol/g) at pH 6.3 from a highly concentrated binary solution containing 0.70 mol/dm3 phosphite, and 0.20 mol/dm3 hypophosphite. Akaganeite can be regenerated and reused for uptake of phosphite with an exchange capacity equivalent to that of the original akaganeite.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476430

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 964-971

Titre :	Equilibrium and kinetics of reactiveextraction of ibuprofen enantiomers from organic solution by hydroxypropyl - B - cyclodextrin
Type de document :	texte imprimé
Auteurs :	Kewen Tang, Auteur ; Jian Cai, Auteur ; Panliang Zhang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 964-971
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Enantiomer Kinetics
Résumé :	This paper reports on the equilibrium and kinetics of the reactive extraction of hydrophobic ibuprofen (IBU) enantiomers from the organic phase to the aqueous phase by hydroxypropyl-β-cyclodextrin (HP-β-CD). The modeling and experimental data of extraction performance factors were investigated to obtain the optimal extraction conditions. The best conditions identified involve the use of an HP-β-CD concentration of 0.03 mol/L and pH value of 2.5 at 10 °C. The theory of extraction accompanied by chemical reactions was used to obtain the intrinsic kinetics of the extraction of IBU enantiomers by HP- β-CD. The effects of process parameters, including the agitation speed, interfacial area, initial concentration of IBU enantiomers, initial concentration of extractant, and pH value of aqueous phase, on the initial extraction rate were separately studied. The reactions are first order in IBU and second order in HP-β-CD with forward rate constants of 7.21 x 10―4 m6/(mol2·s) for S-LBU and 4.58 × 10―4 m6/(mol2·s) for R-IBU, respectively.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476429

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 954-963

Titre :	Selective sulphide precipitation of heavy metals from acidic polymetallic aqueous solution by thioacetamide
Type de document :	texte imprimé
Auteurs :	Mahdi Gharabaghi, Auteur ; Mehdi Irannajad, Auteur ; Amir Reza Azadmehr, Auteur
Année de publication :	2012
Article en page(s) :	pp. 954-963
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Aqueous solution Heavy metal
Résumé :	The selective separation and recovery of copper, cadmium, zinc, and nickel from a polymetallic solution with sulphide precipitation using thioacetamide have been investigated. Selective metal sulphide precipitation was studied as a function of pH, contact time, and temperature. The results showed that it was possible to separate metals by accurately controlling the pH and temperature. Below pH 2.5, copper precipitation was complete. The cadmium, zinc, and nickel selective precipitations were performed at pH of 4, 5.5, and 7.5, respectively. Temperature also had important effects on the selective separation, and metals precipitation yields increased with increasing temperature. Thioacetamide hydrolysis kinetics and its activation energies in various conditions were calculated. The metal sulphide precipitates were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the results showed that the produced precipitates had high purity.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476428

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 944–953

Titre :	Organic – inorganic hybrid silica membranes with controlled silica network size for propylene / propane separation
Type de document :	texte imprimé
Auteurs :	Masakoto Kanezashi, Auteur ; Mitsuki Kawano, Auteur ; Tomohisa Yoshioka, Auteur
Année de publication :	2012
Article en page(s) :	pp. 944–953
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Hybrid silica membranes
Résumé :	Bis(triethoxysilyl)methane (BTESM), which consists of Si–C–Si bonds, was used as a membrane precursor to control the size of amorphous silica networks. The single gas permeation characteristics of hybrid silica membranes were examined to determine the effect of silica precursors on amorphous networks. Pore size distribution, as determined by single gas permeation, suggested that average pore size was in the following order: bis(triethoxysilyl)ethane (BTESE)-derived silica > BTESM-derived silica > tetraethoxysilane (TEOS)-derived silica, due to differences in the minimum units of the silica precursor. The high C3H6/C3H8 separation performance of BTESM-derived silica membranes in a wide temperature range (50–200 °C) can be due to the control of silica network size by the “spacer” method using a Si–C–Si unit. For example, a BTESM-derived silica membrane showed a high C3H6 permeance of 6.32 × 10–7 mol m–2 s–1 Pa–1 with a C3H6/C3H8 permeance ratio of 8.8 at 50 °C. The order of C3H6 and C3H8 permeances of BTESM-derived silica membranes was C3H6 > C3H8, independent of the number of sol coats and temperature (50–200 °C), although the kinetic diameter of C3H6 (dk = 0.45 nm) was reported to be larger than that of C3H8 (dk = 0.43 nm). For permeation of hydrocarbons through amorphous silica membranes, it is suggested that the kinetic diameter, which is a minimum equilibrium cross-sectional diameter, is not applicable for effective molecular size, probably because diffusivity depends not only on the minimum cross section but also on molecular length.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201606k

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 931-943

Titre :	Validation of Dividing-Wall Columns Based on Experimental Data and Dynamic Simulations : Pilot-Plant and Production-Scale Columns
Type de document :	texte imprimé
Auteurs :	Gerit Niggemann, Auteur ; Georg Fieg, Auteur
Année de publication :	2012
Article en page(s) :	pp. 931-943
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Modeling Production Pilot plant Dynamic model
Résumé :	Dividing-wall columns are a promising separation device in terms of energy efficiency because they are suitable for the complete separation of ternary mixtures. The increased application of this progressive technology is based on reduced capital and operating costs. Although several articles have already been published in the field of dividing-wall columns, reliable knowledge is still missing concerning the dynamics of this separation process. To bridge this gap, experimental data on the process dynamics of dividing-wall columns around a steady-state operating point are presented herein, together with extensive model validation of the transient behavior of dividing-wall columns. Furthermore, the process model was successfully compared with experimental data from a production-scale dividing-wall column, which emphasizes the validity of the model. Thus, the validated process model serves as a virtual plant and can be used to develop and test future process control structures. Moreover, the knowledge gained from this study will help to increase the acceptance of dividing-wall columns in industry.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476426

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 925-930

Titre :	Solubility and diffusivity of N2O in aqueous 4 - (Diethylamino) - 2 - butanol solutions for use in postcombustion CO2 capture
Type de document :	texte imprimé
Auteurs :	Teerawat Sema, Auteur ; Mohamed Edali, Auteur ; Abdulaziz Naami, Auteur
Année de publication :	2012
Article en page(s) :	pp. 925-930
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Carbon dioxide Diffusion coefficient Solubility
Résumé :	In this work, the solubility and diffusivity of nitrous oxide (N2O) in aqueous 4-(diethylamino)-2-butanol (DEAB) solutions were measured. Solubility was measured in a stirred cell reactor over the temperature range of 298―343 K and concentration range of 0.68―3.77 M. On the other hand, diffusivity was measured in a laminar jet absorber over the temperature range of 298―318 K and concentration range of 1.0―2.5 M. An attempt was made to correlate the solubility data with well-known models (semiempirical model, Redlich―Kister equation, and polynomial model). It was observed that only the polynomial model correlated the solubility of N2O in aqueous DEAB solution satisfactorily with an AAD of 0.1%. Similarly, an attempt was made to correlate the diffusivity data with well-known models (semiempirical model and modified Stokes-Einstein model). The semiempirical model provided better predicted N2O diffusivity data compared with the experimental data with an AAD of 3.4%. These data can then be used to determine the physical solubility and physical diffusivity of carbon dioxide (CO2) in aqueous DEAB solutions using the "N2O analogy".
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476425

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 915-924

Titre :	Multiscale simulation and experimental study of novel SiC structured packings
Type de document :	texte imprimé
Auteurs :	Xingang Li, Auteur ; Guohua Gao, Auteur ; Luhong Zhang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 915-924
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Ordered packing
Résumé :	Two SiC corrugated structured packings are developed: one being smooth plate and the other made of porous SiC foam. Accordingly, a macroscale three-dimensional (3D) geometric module of two corrugated sheets is introduced with a periodic boundary and a microscale computational geometry is gained from arrayed tetrakaidecahedrons. Single-phase modeling is carried out in the macro module to determine the dry pressure drops for the two types of packing. The results show that the porous SiC packing has a higher pressure drop than that of the smooth one. Two-phase flow for smooth packing is simulated with a VOF-like model provided by CFX in the macroscale geometry. It is found that openings in corrugated plates can improve the film distribution and mass-transfer efficiency. Microsimulation of two-phase flow in the porous SiC packing is performed, and the results prove that liquid can go inside the SiC foam and extend along the foam matrix with a velocity. Therefore, the porous foam can provide a larger effective gas―liquid interfacial area for mass transfer, which explains its larger theoretical plate number, compared to the smooth packing. Performance parameters including pressure drop and liquid holdup have been measured to validate the simulation method, while the distillation experiments have been carried out to study the mass-transfer efficiency of the novel SiC packings.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476424

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 900-914

Titre :	Fluoride removal from water using bio - char, a green waste, low - cost adsorbent : Equilibrium uptake and sorption dynamics modeling
Type de document :	texte imprimé
Auteurs :	Dinesh Mohan, Auteur ; Rupa Sharma, Auteur ; Vinod K. Singh, Auteur
Année de publication :	2012
Article en page(s) :	pp. 900-914
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Modeling Dynamic model Sorption Uptake
Résumé :	Drinking water containing fluoride > 1 mg/L is unsafe for human consumption. Higher intake of fluoride can cause potential health hazards. Low-cost pine wood and pine bark chars, obtained as a byproduct from fast pyrolysis in an auger reactor at 400 and 450 °C, were characterized and used as received for water defluoridation. Sorption studies were performed at different temperatures, pH values, and solid to liquid ratios in the batch mode. Maximum fluoride adsorption occurred at pH 2.0. A kinetic study yielded an optimum equilibrium time of 48 h with an adsorbent dose of 10 g/L. Sorption isotherm studies were conducted over a concentration range of 1-100 mg/L. Fluoride adsorption decreased with an increase in temperature. The char performances were evaluated using the Freundlich, Langmuir, Redlich―Peterson, Toth, Temldn, Sips, and Radke adsorption models. Based on average percent error, the best isotherm fits follow the orders for pine wood and pine bark: PWLangmuir ≈ PWRedlich-Peterson > PWToth > PWSips > PWRadke-Prusnitz ≈ PWFreundlich > PWTemkin and PBToth > PBRadke-Prausnitz ≈PBFreundlich > PBRedlich-Peterson > PBLangmuir > PBSips > PBTemkin. The pine chars successfully treated fluoride-contaminated groundwater at pH 2.0. The chars swelled in water due to their high oxygen content (8―11%), opening new internal pore volume. Fluoride could also diffuse into portions of the chars'subsurface solid volume promoting further adsorption. Ion exchange and metal fluoride precipitation are modes of adsorption. Remarkably, these chars (SBET: 1―3 m2g―1) can remove similar amounts or more fluoride than activated carbon (SBET: ∼1000 m2g―1).
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476423

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 891-899

Titre :	n - Propyl propionate synthesis via catalytic distillation - experimental investigation in pilot - scale
Type de document :	texte imprimé
Auteurs :	Carsten Buchaly, Auteur ; Peter Kreis, Auteur
Année de publication :	2012
Article en page(s) :	pp. 891-899
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Distillation Catalytic reaction
Résumé :	Catalytic distillation experiments were designed and carried out in a pilot-scale column to prove the technical feasibility of the heterogeneously catalyzed n-propyl propionate synthesis by esterification of propionic acid with 1-propanol using the surface-sulfonated ion-exchange resin Amberlyst 46. The experiments cover a broad range of decisive operational parameters, for example, reflux ratio, column load, distillate-to-feed ratio, and molar feed ratio of the reactants. The reconciled results comprise a complete set of concentration and temperature profiles along the column height and, hence, exhibit detailed and reliable data for model validation purposes.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476422

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 882-890

Titre :	Experimental investigation of a novel polymeric heat exchanger using modified polypropylene hollow fibers
Type de document :	texte imprimé
Auteurs :	Yuchun Qin, Auteur ; Baoan Li, Auteur ; Shichang Wang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 882-890
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Hollow fiber Heat exchanger
Résumé :	Plastic heat exchangers have attracted more and more attention because of their superior resistance to chemicals and fouling. However, the thermal conductivity of plastic materials is much lower than that of metal, which limits the wider application of plastic heat exchangers. In this study, polypropylene-based hollow fibers as a heat-conducting medium for heat exchangers was developed by melt-mixing polypropylene with graphite particles and maleated polypropylene (PP-g-MA). Results show that the addition of graphite fairly improved the crystalline, thermal stability and conductivity of the polypropylene resin and further improved the heat transfer efficienry of polypropylene-based hollow fiber heat exchangers. The overall heat transfer coefficient of 15.0 wt % graphite modified polypropylene hollow fiber heat exchangers reached 1228.7 W/(m2·K), which is 5 times higher than that of pure PP-based hollow fiber heat exchangers, and the overall conductance per unit volume reached 1.1 × 106 W/(m3·K). Further, the heat transfer efficiency increases fairly with the increase of the fluid flow rate, especially with the flow rate of the tube- side. The optimized operation mode is that the hot water flows on the tube-side and the cold water flows on the shell-side.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476421

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 872-881

Titre :	Robust iterative learning control with quadratic performance index
Type de document :	texte imprimé
Auteurs :	Zuhua Xu, Auteur ; Jun Zhao, Auteur ; Yi Yang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 872-881
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Learning
Résumé :	In this paper, a robust iterative learning control (ILC) designed through a linear matrix inequality (LMI) approach is proposed first, based on the worst-case performance index with ellipsoidal uncertainty and polytopic uncertainty, respectively. Since the design based on worst-case performance index is too conservative, a novel ILC design based on nominal performance index is further proposed, and its robust convergence properties are proven. The latter can give better performance when the nominal model is dose to the true process. Simulations have demonstrated the effectiveness and excellent performance of the proposed methods.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476420

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 860-871

Titre :	Optimal feed point design and regulation of a novel plate reactor
Type de document :	texte imprimé
Auteurs :	Yingying Chen, Auteur ; Karlene A. Hoo, Auteur
Année de publication :	2012
Article en page(s) :	pp. 860-871
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Reactor Regulation Design
Résumé :	This work uses an open-loop analysis of a novel plate reactor to determine the optimum number of feed points and their locations to achieve maximum conversion. Once the open-loop design is optimized, a control system is designed to achieve maximum conversion of the reactants by regulating the reactor temperature using discrete proportional-integral-derivative (PID) controllers. It was found that the optimum number of feed points is two, equidistantly spaced from each other, and also that a PID controller design based on the internal model control method gives the best closed-loop performance.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476419

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp.848–859

Titre :	Optimization of water systems with the consideration of pressure drop and pumping
Type de document :	texte imprimé
Auteurs :	Szu Wen Hung, Auteur ; Jin-Kuk Kim, Auteur
Année de publication :	2012
Article en page(s) :	pp.848–859
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Optimization Water Pressure Pumping
Résumé :	Novel automated design method has been developed to consider impacts of pressure drop and pumping arrangement in the water network in which water reuse is exploited to reduce freshwater consumption in process industries. A superstructure-based optimization framework has been developed to systematically consider all the key design issues simultaneously, including flow rate constraints, pressure-drop constraints, and other operational constraints, as well as to fully accommodate rigorous economic trade-off between freshwater cost, piping cost, and pumping cost. The proposed optimization study enables the identification of the optimal distribution of water within the network, together with the most appropriate location and capacity of pumps required for water systems. A robust and reliable solution strategy has been developed to effectively deal with computational difficulties associated with solving a mixed-integer nonlinear programming problem, with the aid of the effective application of physical insights gained from conceptual understanding of the design problem. The network complexity has been readily controlled by imposing design constraints in the optimization. Examples have been provided to prove the effectiveness of the design method developed in this paper and to demonstrate the importance of considering pressure drop constraints in practice.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201775y?mi=snxuk8&af=R&pageSize=20&searchT [...]

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 835-847

Titre :	Optimal design of a rotating packed bed for VOC stripping from contaminated groundwater
Type de document :	texte imprimé
Auteurs :	Krishna Gudena, Auteur ; G.P. Rangaiah, Auteur ; S. Lakshminarayanan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 835-847
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Water pollution Ground water Stripping Volatile organic compound Packed bed Optimal design
Résumé :	Groundwater pollution by volatile organic compounds (VOCs) is a serious environmental concern, and several techniques have been suggested and employed to strip off these harmful compounds. Since groundwater is classified as a distributed scale system, an efficient VOC stripping system should be portable and economically competitive. The focus of the current study is to remove trichloroethylene (TCE) from contaminated groundwater in a rotating packed bed (high gravity or HiGee). Although industrial applications of HiGee do exist, studies on optimal design of the same is scarce in the literature. The present study optimizes the design of an industrial-scale HiGee stripping process with conflicting objectives such as total annual cost (TAC) and total VOC removal under consideration. The synergy effect of heating and rotation is studied, and several inferences from this study are listed. Pareto-optimal solutions obtained provide a wide range of optimized design alternatives, one of which can be chosen and employed by the designers, as per their end needs. Component-wise power consumption, uncertainty analysis, and sensitivity analysis of the involved parameters and variables are also studied to provide further insights into the process.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476417

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 814-834

Titre :	Planning under Demand and Yield Uncertainties in an Oil Supply Chain
Type de document :	texte imprimé
Auteurs :	Kailiang Tong, Auteur ; Yiping Feng, Auteur
Année de publication :	2012
Article en page(s) :	pp. 814-834
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Uncertainty Planning
Résumé :	In this article, a stochastic programming approach for an optimal refinery planning problem under uncertainties is proposed. The nominal planning model is extended by means of conditional value-at-risk theory. Demand amount uncertainty and product yield fluctuation are taken into account simultaneously. The risk of customer dissatisfaction and inventory violation are considered as constraints according to the decision maker's risk tolerance. Sample average approximation approach is employed to test the robustness of the model and determine the suitable risk aversion value. A more accurate product yield distribution based upon a Markov chain is introduced and applied in this model. A problem with such endogenous uncertainty is solved using a heuristic iterative algorithm integrating stochastic programming and simulation framework. Also, the scenario number in the stochastic programming model is determined by a statistical analysis, which is a compromise of model accuracy and problem size. At the end of this article, a comprehensive analysis is presented to illustrate the effectiveness of the proposed model.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476416

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 807-813

Titre :	Electric relaxational effects induced by displacement current in dielectric materials
Type de document :	texte imprimé
Auteurs :	Jan Jadzyn, Auteur ; Jolanta Swiergiel, Auteur
Année de publication :	2012
Article en page(s) :	pp. 807-813
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Dielectric materials
Résumé :	An investigation was carried out on frequency behavior of the complex electric modulus, the impedance and the conductance, related to the displacement current resulting from the normal Brownian dynamics of relaxing molecular dipoles in dielectric materials. The experiment was performed for the liquid crystalline smectic A phase of n-octylcyanobiphenyl (8CB) in the frequency region of 200 kHz―50 MHz, where the single dielectric relaxation of the Debye-type occurs and, at the same time, the ionic conductivity in the compound is negligibly low (σDC ≈ 0).
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476415

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 4824-4837

Titre :	Coalescence of bubbles in aqueous alcohol solutions
Type de document :	texte imprimé
Auteurs :	Ayanavilli Srinivas, Auteur ; Pallab Ghosh, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4824-4837
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Foam Modeling Prediction Stochastic model Stability Hydration Micellar critical concentration Surface tension Gas liquid interface Air water interface Adsorption Alcoholic solution Surfactant Aliphatic compound Non ionic surfactant Aqueous solution Bubble Coalescence
Résumé :	Coalescence of air bubbles in aqueous solutions of two aliphatic alcohols (viz. butanol and hexanol) and four nonionic surfactants (viz. Tween 20, Tween 40, Tween 60 and Tween 80) is reported in this work. Single-component alcohol and surfactant solutions as well as mixed binary surfactant-alcohol solutions were studied. Adsorption of the surface active compounds at air-water interface was studied by measuring the surface tension of the aqueous solutions. The critical micelle concentration and surface tension at this concentration were determined for the single and mixed surfactant-alcohol systems. The effect of concentration of surface active compounds on coalescence of air bubbles at flat air-water interface was studied. The role of electrostatic double layer, hydration and steric forces on coalescence was investigated. It was found that the stability of the thin aqueous films in mixed surfactant-alcohol systems depends on the subtle interplay of the intermolecular and surface forces in the film, which vary with the composition of the monolayer at the air-water interface. Stochastic distributions of coalescence time were observed in all systems. The coalescence time distributions were fitted by the stochastic model. The mean values of the distributions were compared with the predictions of seven film-drainage models.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=24493381

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 788-794

Titre :	Enhanced wet - chemical etching to prepare patterned silicon mask with controlled depths by combining photolithography with galvanic reaction
Type de document :	texte imprimé
Auteurs :	Nannan Sun, Auteur ; Jianming Chen, Auteur ; Chao Jiang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 788-794
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Chemical etching
Résumé :	We have developed an enhanced wet-chemical method to prepare patterned silicon templates with controlled depths at microscale by combining photolithography with electroless metal etching. The silicon masks are obtained in the following procedures: patterned silicon wafers selectively etch through galvanic reactions and result in patterned surfaces with silicon nanoarrays in exposed areas during photolithography; the as-etched silicon wafers are corroded in a mixture etching solution to remove silicon nanoarrays, leading to patterned silicon templates.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476413

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 780-787

Titre :	Schinopsis iorentzii extract as a green corrosion inhibitor for low carbon steel in 1 M HCl solution
Type de document :	texte imprimé
Auteurs :	Husnu Gerengi, Auteur ; Halil Ibrahim Sahin, Auteur
Année de publication :	2012
Article en page(s) :	pp. 780-787
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Carbon steel Corrosion inhibitor Extract
Résumé :	The corrosion inhibition of low carbon steel in 1 M HCl solution with different concentrations of Schinopsis lorentzii extract was studied using Tafel extrapolation, linear polarization, and electrochemical impedance spectroscopy (EIS). It was found that Schinopsis lorentzii extract acted as slightly cathodic inhibitor and inhibition efficiencies increased with the increase of extract concentration. The adsorption of the molecules of the extract on the low carbon steel surface was in accordance with the Temkin adsorption isotherm. The results showed that Schinopsis lorentzii extract could serve as a corrosion inhibitor of the low carbon steel in hydrochloric acid environment.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476412

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 775–779

Titre :	Red mud from brazil : Thermal behavior and physical properties
Type de document :	texte imprimé
Auteurs :	Maria Lúcia Pereira Antunes, Auteur ; Sara Jane Couperthwaite, Auteur ; Fabiano Tomazini Da Conceiçao, Auteur
Année de publication :	2012
Article en page(s) :	pp. 775–779
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Thermal behavior
Résumé :	The main constituents of red mud produced in Aluminio city (S.P., Brazil) are iron, aluminum, and silicon oxides. It has been determined that the average particle diameter for this red mud is between 0.05 and 0.002 mm. It is observed that a decrease in the percentage of smaller particles occurs at temperatures greater than 400 °C. This observation corresponds with the thermal analysis and X-ray diffraction (XRD) data, which illustrate the phase transition of goethite to hematite. A 10% mass loss is observed in the thermal analysis patterns due to the hydroxide–oxide phase transitions of iron (primary phase transition) and aluminum (to a lesser extent). The disappearance and appearance of the different phases of iron and aluminum confirms the decomposition reactions proposed by the thermal analysis data. This Brazilian red mud has been classified as mesoporous at all temperatures except between 400 and 500 °C where the classification changes to micro/mesoporous.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201700k

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 767-774

Titre :	Synthesis and characterization of acicular iron oxide particles obtained from acid mine drainage and their catalytic properties in toluene oxidation
Type de document :	texte imprimé
Auteurs :	Silvia L. F. Andersen, Auteur ; Rubia G. Flores, Auteur ; Vivian S. Madeira, Auteur
Année de publication :	2012
Article en page(s) :	pp. 767-774
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Oxidation Catalytic reaction Acid mine drainage
Résumé :	Acid mine drainage (AMD) has long been a significant environmental problem resulting from the microbial oxidation of iron pyrite in the presence of water and air. This Article describe a method to produce acicular goethite particles (AGNs) from AMD and their application as a catalyst for the combustion of volatile organic compounds. Ferric ions were recovered from AMD as AGNs with relatively high purity via an oxidation-selective precipitation process during AMD treatment. Hematite materials (PNs) were produced when the AGNs were treated at 450 °C. These materials were characterized by XRD, SEM, TGA, and N2 adsorption/desorption. The PNs were tested as a combustion catalyst and shown to be useful for the oxidation of toluene. AGNs impregnated with manganese were used to prepare the PN_Mn5 catalyst. The catalysts selectively produced CO2 and water, representing a good alternative to commercially available catalysts in terms of origin and availability.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476410

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 758-766

Titre :	Modeling the volumetric properties of ionic liquids using modified perturbed hard - sphere equation of state : Application to pure and binary mixtures
Type de document :	texte imprimé
Auteurs :	Hosseini, S. M., Auteur ; J. Moghadasi, Auteur ; M. M. Papari, Auteur
Année de publication :	2012
Article en page(s) :	pp. 758-766
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Thermodynamic properties Binary mixture Equations of state Ionic liquid Modeling
Résumé :	In this paper, an alternative corresponding states correlation was applied to the perturbed hard-sphere equation of state (PHS EOS) to improve the predictive power of this EOS for modeling the volumetric properties of ionic liquids (ILs) and their mixtures. Two temperature-dependent parameters appearing in the EOS have been determined using two reliable scaling constants, the surface tension and the liquid density, both at room temperature. The predictive power of the proposed model has been assessed by comparing the results with 2366 experimental data points over a broad range of pressores and temperatures. The overall average absolute deviation (AAD) of the calculated densities from literature data was found to be 0.77%. Generally, this work shows that the PHS EOS based on the surface tension property of ILs outperforms the PHS EOS based on critical properties. Moreover, the improved PHS EOS has been applied to predict the volumetric properties of 16 binary mixtures involving ILs. The second partners of binary mixtures studied in this work are water, ethanol, methanol, acetone, acetonitrile, propylene carbonate, and I-propanol. Furthermore, the binary mixtures of ILs have also been studied. From 1685 data points examined for the aforementioned binary mixtures, the AAD of the calculated densities and the excess volumes from those reported in the literature were found to be 0.38 and 0.56%, respectively. Finally, the nonadditivity behavior of the studied mixtures is also investigated. The sign of the nonadditivity parameter indicates a tendency toward attraction between the unlike molecules in the mixture. However, the value of this parameter is not large, which implies that the hard-sphere model is able to model the excess properties of the present mixtures.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476409

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 751-757

Titre :	Study on ester - amide exchange reaction between PBS and PA6lcoT
Type de document :	texte imprimé
Auteurs :	Zhen Yao, Auteur ; Jia-ming Sun, Auteur ; Qiang Wang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 751-757
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Exchange reaction
Résumé :	To improve the thermal properties and mechanical properties of synthetic biodegradable polymers, poly(butylene succinate) (PBS) and poly(hexamethylene isophthalamide-co-terephthalamide) (PA6IcoT) are reactively blended in a LIST corotating processor under melting conditions. The products are fractionated into insoluble and soluble parts using chloroform as the solvent. The Fourier transform infrared spectra of these two fractions confirm that the exchange reaction between PA6IcoT and PBS occurs when p-toluenesulfonic acid is used as the catalyst. On the basis of the 13C NMR analysis, the pathway of the exchange reaction is described. The extent of exchange reaction, average length of the various sequences, and degree of randomness in the reactive blends are calculated. It has been found that the randomness of copolymers is increased with the increase in reaction extent. Scanning electron microscopy (SEM) is employed to investigate morphology development of the reactive blends. It shows that the copolymers generated by the exchange reaction act as the compatibilizer to improve the compatibility of PBS and PA6IcoT. The fraction of PA6IcoT- and PBS-rich phases is significantly reduced with increasing reaction extent.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476408

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 741–750

Titre :	Thermogravimetry analysis of CO2 and H2O reduction from solar nanosized Zn powder for thermochemical fuel production
Type de document :	texte imprimé
Auteurs :	Stéphane Abanades, Auteur
Année de publication :	2012
Article en page(s) :	pp. 741–750
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Production Fuel Powder Carbon dioxide Thermogravimetry
Résumé :	This study addresses the thermochemical production of CO and H2 as high-value solar fuels from CO2 and H2O using reactive Zn nanoparticles. A two-step thermochemical cycle was considered: Zn-rich nanopowder was first synthesized from solar thermal ZnO dissociation in a high-temperature solar chemical reactor and the reduced material was then used as an oxygen carrier during the CO2 and H2O reduction reactions. The kinetics of CO2 and H2O reduction was investigated by thermogravimetry to demonstrate that the solar-produced nanopartides react efficiently with CO2 and H2O. Zn started to react from 513 K and almost complete Zn conversion (reaction extent over 95%) was achieved at 633―773 K in less than 5 min, thus confirming that the active Zn-rich nanopowder exhibits rapid fuel production kinetics during H2O and CO2 dissociation. The reaction mechanism was best described by a nucleation and growth model with an activation energy of 43 kJ/mol and an oxidant order of 0.8. The high reactivity of zinc was attributed to the specific solar synthesis route involving ZnO thermal dissociation and condensation of Zn vapor as nanoparticles.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476407

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 732–740

Titre :	Solvent free selective oxidation of styrene and benzyl alcohol to benzaldehyde over an eco - friendly and reusable catalyst, undecamolybdophosphate supported onto neutral alumina
Type de document :	texte imprimé
Auteurs :	Anjali Patel, Auteur ; Soyeb Pathan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 732–740
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Catalyst Oxidation
Résumé :	Supported undecamolybdophosphate was synthesized and characterized by various physicochemical techniques and successfully used for solvent free oxidation of styrene and of benzyl alcohol to benzaldehyde. Influence of the reaction parameters (molar ratio of substrate to H2O2, amount of the catalyst, reaction time, and reaction temperature) were studied. The catalyst was reused three times without any significant loss in the catalytic activity. FT-IR, XRD, and DRS of regenerated catalyst indicated that the catalyst was undegraded and stable after the reaction. The novelty of the work lies in obtaining a single selective product, benzaldehyde, as well as a high TON for the same, under mild conditions.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476406

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012)

Titre :	High photocatalytic activity of magnetically separable manganese ferrite – graphene heteroarchitectures
Type de document :	texte imprimé
Auteurs :	Yongsheng Fu, Auteur ; Pan Xiong, Auteur ; Haiqun Chen, Auteur
Année de publication :	2012
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Photocatalysis
Résumé :	A simple and straightforward strategy was developed to fabricate magnetically separable MnFe2O4―grapbene photocatalysts with differing graphene content. It was found that graphene sheets were fully exfoliated and decorated with MnFe2O4 nanocrystals having an average diameter of 5.65 nm and a narrow particle size distribution. It is very interesting that, although MnFe2O4 alone is photocatalytically inactive under visible light irradiation, the combination of MnFe2O4 nanoparticles with gaphene sheets leads to high photocatalytic activity for the degradation ofmethylene blue under visible light irradiation. The strong magnetic property of MnFe2O4 nanoparticles can be used for magnetic separation in a suspension system, and therefore it does not require additional magnetic components as is the usual case. Consequently, the MnFe2O4―graphene system becomes a dual function photocatalyst. The significant enhancement in photoactivity under visible light irradiation can be ascribed to the reduction of gaphene oxide (GO), because the photogenerated electrons of MnFe2O4 can transfer easily from the conduction band to the reduced GO, effectively preventing a direct recombination of electrons and holes. Hydroxyl radicals play the role of main oxidant in the MnFe2O4―graphene system, and the radicals' oxidation reaction is obviously dominant.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476405

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 719-724

Titre :	Effect of macropore formation in Pt catalyst supports on the oxidation activity for diesel fuel mist
Type de document :	texte imprimé
Auteurs :	Junko Uchisawa, Auteur ; Akira Obuchi, Auteur ; Tetsuya Nanba, Auteur
Année de publication :	2012
Article en page(s) :	pp. 719-724
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Diesel fuel Oxidation Catalyst support Macroporosity
Résumé :	The effect of macropore formation in catalyst supports on the oxidation activity for diesel fuel mist was examined with the goal of improving catalyst efficiency. To investigate the effect on a laboratory scale using granular samples, we designed a reaction system that supplied fuel mist to the catalyst bed directly by an air atomizing nozzle. The catalytic activity was found to be improved by macropore formation in the support. This effect was also demonstrated for a washcoated catalyst on a honeycomb with diesel engine exhaust. These results suggest that the macropore diffusion channels are secure even if fuel mist attaches to the support surface, and the reactant gas can diffuse to the interior of the support and reach the active sites. Macropore formation prevented the blockage of pores of the support surface and thus the active sites of the catalyst.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476404

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 710-718

Titre :	Kinetic study of methanol synthesis over CuO / ZnO / Al2O3 / V2O3 catalyst deposited on a stainless steel surface
Type de document :	texte imprimé
Auteurs :	David Perko, Auteur ; Janez Levec, Auteur
Année de publication :	2012
Article en page(s) :	pp. 710-718
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Stainless steel Catalyst Kinetics
Résumé :	A spraying method for coating stainless steel surfaces with a commercial methanol synthesis catalyst was studied for the purpose of making a thin, active, and durable plate catalyst. The catalyst slurry was composed of CuO/ZnO/Al2O3/V2O3 powder dispersed in 2-propanol and was sprayed on a curved stainless steel surface. The coating was found to exhibit good adhesion to the metal surface and to provide a considerable increase in surface area relative to the geometrical area of the metal support surface (up to a factor of 11000). The effects of key method parameters, namely, the size of the catalyst particles in the suspension and the coating thickness, on the efficiency of coating and the morphology and durability of the coating were briefly investigated. The intrinsic kinetics of carbon dioxide and carbon monoxide hydrogenation, as well as the WGS reaction, on the prepared plate catalyst were evaluated and compared to literature data. The reactions were carried out in a continuous stirred-tank reactor (CSTR) system appropriately assembled with a curved plate catalyst in the absence of mass-transfer limitations.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476403

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 704-709

Titre :	Enhanced and selective degradation of pollutants over cyclodextrin / TiO2 under visible light irradiation
Type de document :	texte imprimé
Auteurs :	Xu Zhang, Auteur ; Xuankun Li, Auteur ; Nansheng Deng, Auteur
Année de publication :	2012
Article en page(s) :	pp. 704-709
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Visible radiation Titanium oxide Pollutant
Résumé :	The photocatalytic performance of cydodextrin modified TiO2 (TiO2/β-CD) on the degradation of rhodamine B and bisphenol A (BPA) was studied in this work. The interactions between β-CD and TiO2 varied as the synthesis method changes. When applying TiO2/β-CD synthesized from photoinduced self-assembly method as photocatalyst, the initial visible light (λ ≥ 420 nm) degradation rates R0 of rhodamine B and BPA increased by 4.6 and 3.2 times respectively. The TiO2/β-CD hybrid material synthesized from adsorption method only showed enhancement in dye pollutants degradation. The reactivity of TiO2/β-CD under visible light was correlated with the specific surface area of unmodified semiconductor. The mechanism for the enhanced and selective degradation of pollutants over TiO2/β-CD was also proposed in this work.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476402

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 691-703

Titre :	MathematicalModeling of air – and oxy – coal confined swirling flames on two extended eddy - dissipation models
Type de document :	texte imprimé
Auteurs :	Jingzhang Liu, Auteur ; Sheng Chen, Auteur ; Zhaohui Liu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 691-703
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Flame Vortex Coal Modeling
Résumé :	The mathematical modeling of air― and oxy―coal flames is a great challenge because of the complexity of the turbulence chemistry interactions. However, the different turbulence chemistry interaction models can give very different results. Therefore, an investigation of the effects of these interactions on air― and oay―coal flames is needed, especially with both improved kinetic mechanisms and modified physical parameters. This work presents a numerical investigation of the effects of the interaction models on the characteristics of air― and oxy―coal confined swirling flames. These interaction models are two extended eddy- dissipation models (EDMs), the finite-rate and eddy-dissipation (FRED) model and the eddy dissipation concept (EDC) model. First, two important factors were considered in the oxy―coal combustion simulations, namely, improved global reaction mechanisms and modified physical parameters. Second, with these improvements and modifications, numerical simulations of air― and oxy―coal flames were carried out. The results showed that the flames focus on the horizontal center and propagate forward with a swirling closure shape and that the flame shapes belong to an intensively accelerated flame type IL. Good predictions of the combustion efficiencies were obtained by these two combustion models. Superior predictions of both the exhausted flue gas mixture and the minor carbon monoxide concentration were obtained with the eddy dissipation-chemical equilibrium (EDC) model. However, both ignition delays and temperature fields were better predicted with the kinetic-controlled and mixed-is-burned (FRED) model.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476401

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 682-690

Titre :	Simulation and analysis of an ethylene slurry polymerization system using supercritical propane
Type de document :	texte imprimé
Auteurs :	Zhao Xiaojun, Auteur ; Guo Xiaojun, Auteur ; Cheng Peng, Auteur
Année de publication :	2012
Article en page(s) :	pp. 682-690
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Supercritical state Polymerization
Résumé :	In this paper, a model for an ethylene slurry polymerization system using supercritical propane as a solvent is developed by adopting a set of thermodynamic and kinetic parameters using fundamental chemical engineering principles and Polymers Plus software. The Ziegler-Natta catalyst is characterized by assuming the existence of multiple types of catalyst sites and deconvolution data from gel permeation chromatography to determine the most probable chain-length distribution and relative amounts of polymer produced at each site type. A set of suitable reaction subclasses and kinetic constants for different site types that fit plant conditions is developed, validating our model. The values calculated for production rate, ethylene conversion, residence time, H2/C2H4 molar ratio in the reactor, number-average molecular weight, and polydispersity index are all close to actual values, verifying that our model accurately describes plant conditions.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476400

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 678-681

Titre :	Reactions of sodium peroxide with components of legacy plutonium materials
Type de document :	texte imprimé
Auteurs :	Robert A. Pierce, Auteur ; Dario C. Castiglione, Auteur ; David M. Missimer, Auteur
Année de publication :	2012
Article en page(s) :	pp. 678-681
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Plutonium oxide
Résumé :	Plutonium oxide (PuO2) calcined at >900 °C resists dissolution in nitric acid (HNO3)-potassium fluoride (KF) solutions commonly used for their dissolution. The Savannah River National Laboratory (SRNL) has developed an alternate method for large samples of PuO2-bearing materials using sodium peroxide (Na2O2) fusion as a pretreatment. The products of the reaction between Na2O2 and PuO2 have been reported in the literature. As part of the SRNL development effort, additional data about the reaction between Na2O2 and PuO2 were required. Also needed were data concerning the reaction of Na2O2 with other components that may be present in the feed materials. Sodium peroxide was reacted with aluminum metal (Al), beryllium metal (Be), graphite, potassium chloride (KCl), magnesium chloride (MgCl2), and calcium chloride (CaCl2). The paper reports and discusses the reaction products of these and related compounds with Na2O2.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202277m

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 668-677

Titre :	Corrosion inhibition and adsorption behavior of punica granatum extract on mild steel in acidic environments : Experimental and theoretical studies
Type de document :	texte imprimé
Auteurs :	Maduabuchi A. Chidiebere, Auteur ; Cynthia E. Ogukwe, Auteur ; Kanayo L. Oguzie, Auteur
Année de publication :	2012
Article en page(s) :	pp. 668-677
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Mild steel Extract Adsorption Corrosion inhibition
Résumé :	The adsorption and corrosion inhibiting effect of aqueous extracts of Punica granatum (PNG) on mild steel in 1 M HCl and 0.5 M H2SO4 at 30 ± 1 °C was investigated using gravimetric, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization techniques. The experimental findings revealed that PNG inhibited the corrosion reaction in both acid environments. Impedance results indicate that the extract organic matter was adsorbed on the metal/solution interface, while polarization data show that the extract behaved mostly as a mixed-type inhibitor. A theoretical study of the adsorption behavior of some of the components of the crude extracts was carried out in the framework of the density functional theory (DFT).
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476398

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 662–667

Titre :	Lime treatment of prehydrolysis liquor from the kraft - based dissolving pulp production process
Type de document :	texte imprimé
Auteurs :	Jing Shen, Auteur ; Pedram Fatehi, Auteur ; Pendar Soleimani, Auteur
Année de publication :	2012
Article en page(s) :	pp. 662–667
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Prehydrolysis liquor
Résumé :	In this study, the concept of using lime for the treatment of industrially produced prehydrolysis liquor (PHL) of kraft-based dissolving pulp production process was tested, and its effect on the concentrations of acetic acid, furfural, UV lignin, and hemicelluloses was explored. Lime treatment resulted in a significant increase in the acetic acid concentration due to alkaline hydrolysis of the acetyl groups bound to the dissolved hemicelluloses in PHL, and the degradation of sugars. At relatively high lime dosages (e.g., above 1.7%), furfural was completely eliminated, while the lignin concentration decreased by 20–25%. The hemicelluloses concentration can be significantly decreased due to the alkaline oxidative degradation. However, when performed in the absence of oxygen/air by bubbling carbon dioxide to the lime/PHL system, the degradation of hemicelluloses was effectively minimized.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2019195

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 655-661

Titre :	Methylation of glycerol with dimethyl sulfate to produce a new oxygenate additive for diesels
Type de document :	texte imprimé
Auteurs :	Jyh-Shyong Chang, Auteur ; Yu-Da Lee, Auteur ; Lawrence Chao-Shan Chou, Auteur
Année de publication :	2012
Article en page(s) :	pp. 655-661
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Additive Methylation
Résumé :	A new oxygenate additive for diesels (bio or petroleum) was manufactured using glycerol, dimethyl sulfate (DMS), and sodium hydroxide pellets as raw materials. By feeding the dimethyl sulfate into the batch reactor containing the sodium glycerate, a semibatch mode operation enhanced the effective methylation of glycerol. A conventional stirred tank reactor that can produce large quantities of oxygenate additives under a normal atmospheric pressure operation became the main feature of the methylation process. With a 3:2 molar ratio of DMS to glycerol, a 3:1 molar ratio of sodium hydroxide to glycerol, a 0.43:1 molar ratio of water to sodium hydroxide, and a temperature of 343 K at the reaction time of 24 h with the feeding time ofDMS under 12 h, the conversion of glycerol (93.5%) and a combined yield of GDMEs and GTME of 71.2% were achieved for a once-through operation. A product mixture of GDME (20 wt %) and GTME (80 wt %) served as a new oxygenate additive for (bio or petroleum) diesels.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476396

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 649-654

Titre :	Use of gas diffusion electrode for the in situ generation of hydrogen peroxide in an electrochemical flow - by reactor
Type de document :	texte imprimé
Auteurs :	Rafael M. Reis, Auteur ; André A. G. F. Beati, Auteur ; Robson S. Rocha, Auteur
Année de publication :	2012
Article en page(s) :	pp. 649-654
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Reactor Hydrogen production In situ Electrodes Gaseous diffusion
Résumé :	Hydrogen peroxide is a powerful oxidant that finds application in several areas, but most particularly in the treatment of industrial wastewaters. The aim of the present study was to investigate the effects of applied potential and electrolyte flow conditions on the in situ generation of hydrogen peroxide in an electrochemical flow-by reactor with a gas diffusion electrode (GDE). The electrolyses were performed in an aqueous acidic medium using a GDE constructed with conductive black graphite and polytetrafluoroethylene (80:20 w/w). Under laminar flow conditions (flow rate = 50 L/h), hydrogen peroxide was formed in a maximum yield of414mg/L after 2 h at -2.25 Vvs Pt //Ag/AgCl (global rate constant = 3.1 mg/(L min); energy consumption = 22.1 kWh/kg). Under turbulent flow (300 L/h), the maximum yield obtained was 294 mg/L after 2 h at -1.75 V vs Pt//Ag/AgCl (global rate constant = 2.5 mg/(L min); energy consumption =30.1 kWh/kg).
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476395

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 639-648

Titre :	Synthesis of nano calcium oxide from a gastropod shell and the performance evaluation for Cr (VI) removal from aqua system
Type de document :	texte imprimé
Auteurs :	N. A. Oladoja, Auteur ; I. A. Ololade, Auteur ; S.E. Olaseni, Auteur
Année de publication :	2012
Article en page(s) :	pp. 639-648
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Porous nano Calcium oxide
Résumé :	A spongy, porous nano calcium oxide (NC) with point zero charge of 11.80 was synthesized using the shell of a Gastropod (Achatina achatina) via the sol–gel technique. The ability of the NC to adsorb Cr (VI) from aqueous solution was assessed systematically in a batch process via isothermal, kinetic, and variable process optimization procedure. The sorption data had the best fitting for the Langmuir isotherm model and the monolayer sorption capacity (qm, mg/g) value of 125 mg/g was obtained. The initial solution pH had no palpable effect on the monolayer sorption capacity. The amount of sorbed Cr (VI) increased with contact time and initial Cr (VI) concentration and attained equilibrium within 120 min. The fitting of the different kinetic models to the sorption data, by error analysis, using the linear coefficient determinations (r2) and the Chi-square statistical analysis (χ2), showed that the mechanism of the sorption process is better described by the pseudo second order kinetic model. Thermodynamic evaluation showed that the sorption process was spontaneous (ΔGo: −15.27; −14.87 and −14.45 kJ/mol at 303, 313, and 333 °C, respectively), exothermic (ΔH0 = −22.568 kJ/mol) and increased disorder (ΔS0 = 0.0244) appeared on the NC–solution interface during the adsorption process.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201189z

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 629-638

Titre :	Alternatives to HDEHP and DTPA for simplified TALSPEAK separations
Type de document :	texte imprimé
Auteurs :	Jenifer C. Braley, Auteur ; Travis S. Grimes, Auteur ; Kenneth L. Nash, Auteur
Année de publication :	2012
Article en page(s) :	pp. 629-638
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Talspeak process
Résumé :	The TALSPEAK process is an established option for lanthanide/minor actinide separations using solvent extraction. In this process, selective extraction of lanthanides is achieved by contacting a water-soluble aminopolycarboxylate complexant in a concentrated carboxylic acid buffer with a liquid cation exchanging extractant in an immiscible organic diluent. Although TALSPEAK process development has been successful on several levels, studies of the detailed fundamental chemistry have revealed undesirable complex interactions between aqueous and organic solute species. These complications threaten to impair process modeling and could impact engineered operations. In the present work, results are reported describing equilibrium partitioning and phase transfer kinetics trends for trivalent lanthanide ions and americium into bis-2-ethyl(hexyl) phosphoric acid (HDEHP) or structural analog 2-ethyl(hexyl) phosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) organic phases from aqueous lactate solutions containing diethylenetriamine-N,N,N′,N′′,N′′-pentaacetic acid (DTPA), triethylenetetramine-N,N,N′,N′′,N′′′,N′′′-hexaacetic acid (TTHA), or N-(2-hydroxyethyl)ethylenediamine-N,N′,N′-triacetic acid (HEDTA). The undesirable partitioning of Na+, lactic acid, and water into the organic phase is greatly reduced when HEH[EHP] replaces HDEHP as the extractant. TTHA appears to offer little advantage over DTPA in conventional TALSPEAK, but both DTPA and TTHA are too strong for use in combination with HEH[EHP]. The combination of HEDTA with HEH[EHP] achieves good balance and exhibits a nearly flat pH dependence between 2.5 and 4.5, in contrast with conventional TALSPEAK. The latter combination demonstrates more predictable performance than is seen in conventional TALSPEAK, while providing acceptable americium/lanthanide separation factors. The HEDTA/HEH[EHP] combination offers the additional advantage of more rapid phase transfer kinetics for the heavier lanthanides without the need for high concentrations of a lactate buffer.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200285r

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 621-628

Titre :	Defects and minor phases in O + and Zr + Ion Co - implanted SrTiO3
Type de document :	texte imprimé
Auteurs :	Weilin Jiang, Auteur ; Mark E. Bowden, Auteur ; Zihua Zhu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 621-628
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Defect
Résumé :	This article reports on a comprehensive experimental study of 16O+ and 90Zr+ ion co-implanted SrTiO3 (STO) single crystals. In this study, STO was used as a model material to simulate a waste form for disposal of radioactive 90Sr that decays to 90Y and subsequently to 90Zr by emission of β– particles. Sequential 16O+ and 90Zr+ ion implantation at 550 K was performed and Zr and O atomic concentrations of up to 1.5 atom % each in STO were achieved. A number of analytical methods were employed to characterize the implanted STO, including secondary-ion mass spectroscopy, multiaxial ion-channeling analysis, and high-resolution X-ray diffraction. The results show that a high defect concentration was generated and accumulated in STO during the ion implantation, but the crystal structure was not rendered fully amorphous. Thermal annealing at 1273 K leads to a significant defect recovery at the surface with little recovery occurring at the damage peak, where a modest recovery occurs upon further annealing at 1423 K. Some of the implanted Zr species are well aligned with the STO 001 axis, but nearly all are barely located at the substitutional sites due to structural distortion. A minor phase with a tetragonal structure is observed in the Zr distributed region, which has the 001 axis parallel to that of the STO host. The tetragonal phase survived annealing at 1423 K with only a small decrease in the c parameter. A general assessment of the model waste form is also provided in this report.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476392

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp.614–620

Titre :	Iodine confinement into metal – organic frameworks (MOFs) : Low - temperature sintering glasses to form novel glass composite material (GCM) alternative waste forms
Type de document :	texte imprimé
Auteurs :	Dorina F. Sava, Auteur ; Terry J. Garino, Auteur ; Tina M. Nenoff, Auteur
Année de publication :	2012
Article en page(s) :	pp.614–620
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Radioiodine Metal organic
Résumé :	The safe handling of reprocessed fuel addresses several scientific goals, especially when considering the capture and long-term storage of volatile radionuclides that are necessary during this process. Despite not being a major component of the off-gas, radioiodine (I2) is particularly challenging, because it is a highly mobile gas and 129I is a long-lived radionuclide (1.57 × 107 years). Therefore, its capture and sequestration is of great interest on a societal level. Herein, we explore novel routes toward the effective capture and storage of iodine. In particular, we report on the novel use of a new class of porous solid-state functional materials (metal–organic frameworks, MOFs), as high-capacity adsorbents of molecular iodine. We further describe the formation of novel glass-composite material (GCM) waste forms from the mixing and sintering of the I2-containing MOFs with Bi–Zn–O low-temperature sintering glasses and silver metal flakes. Our findings indicate that, upon sintering, a uniform monolith is formed, with no evidence of iodine loss; iodine is sequestered during the heating process by the in situ formation of AgI. Detailed materials characterization analysis is presented for the GCMs. This includes powder X-ray diffraction, scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), thermal analysis (thermogravimetric analysis (TGA)), and chemical durability tests including aqueous leach studies (product consistency test (PCT)), with X-ray fluorescence (XRF) and inductively coupled plasma–mass spectrometry (ICP-MS) of the PCT leachate.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200248g?mi=snxuk8&af=R&pageSize=20&searchT [...]

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 607-613

Titre :	Thermodynamic properties of uranyl minerals : Constraints from calorimetry and solubility measurements
Type de document :	texte imprimé
Auteurs :	Tatiana Y. Shvareva, Auteur ; Jeremy B. Fein, Auteur ; Alexandria Navrotsky, Auteur
Année de publication :	2012
Article en page(s) :	pp. 607-613
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Solubility Calorimetry Thermodynamic properties
Résumé :	More than 50 uranyl minerals, phases containing U6+ as the uranyl UO22+ cation, and hydroxide, carbonate, phosphate, and silicate anions, H2O, and alkali and alkaline earth cations, occur in nature and as corrosion products of spent nuclear fuel. Despite their importance and the need to understand their thermodynamics to predict uranium solubility, fate, and transport in the environment, reliable thermodynamic data have only been available recently. This paper summarizes recent studies of enthalpies of formation using high temperature oxide melt solution calorimetry and Gibbs free energies from solubility experiments. Standud state thermochemical parameters (at 25 °C and I bar) are tabulated and the stability and transformation sequences of these phases are discussed. The enthalpies of formation from oxides are discussed in terms of crystal structure and Lewis acid-base interactions.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25476390

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 51 N° 2

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